Place 1/2 of potatoes and the onion in a large soup pan with about 1 inch of broth. Boil and then reduce to a simmer. While that is cooking, toss remainder of vegetables – except corn – in olive oil and spread on baking sheets. Salt and pepper lightly. Place in oven at 450* and turn over once in a while to prevent burning. When potatoes in pan are very tender, remove from heat and blend with an immersion blender or hand mixer. This should create something close to mashed potatoes. Add the remainder of the broth and stir. Begin adding soy milk (or other) until consistency of chowder base is reached. Add nutritional yeast (optional) and stir. Return to very low heat to simmer. If you end up with a base that is too thin, you can thicken to taste with corn starch or potato starch. When vegetables are close to done, add corn and continue baking until cooked through. After vegetables are done roasting, add to creamed potatoes/broth mixture. Adjust seasoning and serve!